More controls in Dallas

More controls in Dallas
Published: 08 March 2005

As Dallas-Fort Worth struggles to reduce its smog, the state could decide March 9 whether to require stricter controls on pollution from a Midlothian cement plant owned by Dallas-based Texas Industries Inc. Three commissioners who make up the board of the state’s Texas Commission on Environmental Quality will hear TXI’s long-standing request to shut off some of its emission controls during the part of the year that’s outside the so-called ozone season. The company says the control equipment is too expensive to run in the wake of escalating natural gas prices. TXI also is seeking permission to operate under a more lenient air permit and to expand operations.

Clean-air advocates want just the opposite. They hope TCEQ will rule for a stricter permit, citing the region’s ongoing failure to comply with the federal Clean Air Act. "It really, really should be denied," said Wendi Hammond, an attorney and executive director for Downwinders at Risk, made up of plant neighbors, and Blue Skies Alliance, a clean-air advocacy group.

The Environmental Protection Agency designated nine North Texas counties, including Ellis County, where Midlothian is located, "non-attainment" for a stricter eight-hour ozone standard effective June 15, 2004. Nitrogen oxide, or NOx, a pollutant emitted from several cement plants in Midlothian, is one ingredient in ozone, considered a precursor to lung-damaging smog.

The EPA had previously advised TCEQ that TXI must apply for a stricter air permit under the new eight-hour standard if a previous application under the older, less stringent standard, wasn’t resolved by June 15, 2004. "I think the commissioners know this is a huge issue," Hammond said. "It’s a critical key piece as far as D-FW’s air quality. If TXI wants to increase their emissions, then D-FW has to find other reductions. If TCEQ followed the EPA’s guidelines and denied the permit, then TXI would have to find the reductions."

 The TXI plant in Ellis County started up in 1960 and has expanded regularly. It now produces 2.8Mt of cement a year and employs 350 people. In 2001, TXI invested $250m to open a new kiln and now seeks to boost production to 3.4Mt.

TXI now wants to shut off natural-gas-powered control technology installed with the new kiln, except during ozone season, which extends from May to October. Industrial plants that emit 100 tons or more annually of certain regulated pollutants must have an air quality permit when they start up, expand or modify their operations, to show they meet Clean Air Act levels. TCEQ has been reviewing TXI’s permit for more than two years.

Shutting off [the controls] during the off-peak ozone season makes sense, said Randy Jones, a TXI spokesman. "There’s no ozone formation during the winter months and the natural gas is needed to heat homes," Jones said. "Those units use a lot of natural gas." He defended the move, saying the plant’s emissions are largely volatile organic compounds, or VOCs, rather than NOx.

The controversial TXI air permit is the second the commissioners have struggled with this year regarding cement plants in Midlothian, which calls itself the cement capital of the world. The commissioners told Michigan-based Holcim US Inc. in mid-February to get started on a pilot project to clean up emissions from the stacks at its controversial cement plant there. The clean air technology, called selective noncatalytic reduction, or SNCR, will be temporarily installed and tested. SNCR injects an ammonia solution into the gases in the kiln system. The ammonia solution interacts with nitrogen oxide, or NOx, and the result is nitrogen and vapor water. The idea is to reduce Holcim’s emissions of NOx.

It isn’t known how much, if any, NOx might be reduced, according to Holcim. The pilot will look at baseline emissions, then determine any reductions.The directive from TCEQ’s three commissioners was a long time in coming, with controversy surrounding Holcim’s permit dating to the late 1990s. Holcim’s air permit allows it to emit 1540t a year of NOx. It is seeking a permit that would allow 3738t. Abstracted from the Dallas Business Journal.